Chapter 12: The curved space-time carousel
...... At the start of Kip's Social Studies class on Friday of the second week of school, Mr. Thomas announced that he was taking the class over to ESAP.
...... "Especially for Alex," said Mr. Thomas, "I borrowed a VritFlic on young Alexander the Great from the Greek Culture Society. And we can experience it in the ESAP planetarium." Kip thought he detected a touch of resentment in Mr. Thomas's voice.
...... Walking from Founders to the Planetarium Complex, Kip looked forward to watching the Amdexter kids ogle at the neat stuff they had at his school.
...... Dr. Ralph was there to run the equipment and supervise the distribution of the headsets.
...... "Why does science always get the best teaching aids?" said Mr. Thomas, softly, as the kids settled into their seats. Kip overheard it as he sat close to the console.
...... "Don't blame me," said Dr. Ralph equally quietly. "This came with the school. But actually, I don't use them. I prefer live experiments--it's so instructive when they go wrong."
...... A half-hour later, at the conclusion of the VritFlic, Kip removed his headset. He blinked and rubbed his eyes as he re-adjusted to non-virtual reality. Looking over at Alex, he saw that his friend had not removed his headset and was still staring up at the dome. He tapped Alex on the arm. "Hey, Alex. It's over. You can wake up now."
...... "What?" Alex took off his headset. "Boy. It was as if Alexander the Great was talking only to me. So I was watching more of it. And we talked more."
...... "You talked more?"
...... Just then, Mr. Thomas called his class to order and then shepherded them out of the dome.
...... As Kip left the building on route back to Founders, Todd said with a sneer, "Is that all you do at ESAP--sit around watching VritFlics?"
...... That day, Kip's fourth period Phys. Ed.
class met at the sports complex pool for swimming tests. Kip dreaded it. While
he liked splashing around in the water, he wasn't a very good swimmer. And so
he felt very nervous about demonstrating his lack of ability in front of the
athletics master and the rest of his class--and while swimming naked.
...... Trying not to drown, he paddled hard, and was aware of his wake, ripples spreading across the pool--like an electron's ghost wave. Suddenly, he had another non-verbal and non-visual image of the electron's behavior in the two slip experiment. The nature of the wave-particle duality. He switched his concentration from water waves to ghost waves.
...... "Campbell," shouted the athletics master, "what's the matter? Are you all right?"
...... "Yes, sir," Kip gurgled, taking in the unmistakable flavor of chlorine pool water, and returning his attention to the matter of his swim test.
...... A little later, after fifth period Orchestra, as Kip padded across the Dalambertian toward Feynman Hall, he felt comfortable with himself and with his place in the universe. He was beginning to feel at home at school--even at Amdexter. He'd settled in, and the pecking order was well established; he knew which kids were smarter, which ran faster, were bigger and stronger, were nasty, were generally to be avoided because of being weird, having spotty personal hygiene, always borrowing stuff, being a trouble-magnet. He'd learned to avoid obvious dangers: kids wanting to beat him up, masters giving him punishment lines, arguments about whether physics was better than absolutely everything. And, because of the radio station preferring light classical music in the morning, the Beethoven rule had not yet come into play so he'd never been late to breakfast. And most importantly, he was making progress, a little progress anyway, in his understanding of what was really going on with quantum mechanics. And, to his surprise, he had passed his swimming test.
...... This day, the air was crisp and dry, making colors seem more vivid--making the world seem but newly painted. The grass, smelling tart and clean, glistened greener than green. The Dalambertian was alive with squirrels and the occasional rabbit. The sky radiated blue as if through a crystal. Today, life was good.
...... As he ambled through the door into Snack Bar, Kip saw in bold writing on the blackboard,
...... ...... ......
...... ...... ......
...... SPECIAL Gedanken today!
...... ...... ...... ...... ...... Sixth and Seventh period classes canceled.
...... Kip and the other boys puzzled over the
announcement for a few minutes, and then Dr. Ralph came in. He carried a big
mesh bag filled with yellow tennis balls which he plopped down on a table.
...... "It's a beautiful day out!" he exclaimed in a burst of enthusiasm. "Much too nice to be stuck in class."
...... Wolfgang leaned in and whispered to Kip, "Think we could use that excuse when we cut class?"
...... "I have decided that for today," Dr. Ralph continued, "I'll temporarily shift the focus from quantum mechanics to the other great pillar of theoretical physics"--he raised both hands over his head in what looked like a celebration of victory--"relativity theory!"
...... Then, accompanied by his usual pacing, he went on to explain that Einstein had changed the very perception of space and time, combining them into a single concept--space-time. "And he solved the great mystery of gravity." He looked out over his class. "What mystery, you might ask." He paused. "All right. Come on, somebody ask it!"
...... Kip giggled. "What mystery?"
...... "I'm glad you asked that." Dr. Ralph went to the board and drew a big circle--"This is the Sun."--and a small circle--"And here's the Earth." He swiveled around. "So! The pull of gravity between the Sun and the Earth keeps the Earth in orbit around the Sun. But. And Isaac Newton himself wondered this: how can something pull on something else through nothing. He called this 'action at a distance'. How can the Sun and Earth pull on each other through a vacuum?"
...... "Well, I'm not sure how it works exactly," said Wolfgang, "but I think--"
...... "That was a rhetorical question, Wolfgang." Dr. Ralph surveyed the boys. "Okay, okay. I know some of you wise guys know the answer. But bear with me. Einstein's big idea was that gravity could be explained as a curvature in space-time. Now this is a tricky thing to get a feel for. In a curved space, straight lines aren't what we think they are. The concept of distance between points isn't obvious." He picked up his bag of tennis balls. "So we're going to spend some time at the carousel." He tossed the bag up in the air. "I've borrowed these from the athletics department--so you can play catch on a moving carousel--to hopefully build an intuitive understanding of curved space-time. An understanding of gravity. Okay?"
...... "But what about magnets," a kid called out. "They pull on things, and I think they can do it through a vacuum. Is that also because of curved space-time?"
...... Dr. Ralph seemed taken by surprise. "They do pull through a vacuum. But, the case of how magnets work is still sort of open."
...... "Sort of?" asked Wolfgang.
...... "No one's yet been able to explain magnetism coming from a curved space-time. One can think of particles traveling through the vacuum carrying the magnetic force--instead of as a curving of space. Actually, you can think of gravity that way as well. It's two different ways of thinking of the same phenomenon."
...... "Another map, territory problem?" said Kip.
...... "Yes, probably?" Dr. Ralph started toward the door. "Come on! We'll forget magnetism for a while and just play catch to learn about gravity."
...... As the throng of boys left Feynman Hall, Kip looked across at the windows of Founders. There were kids in class behind those windows--and they were stuck there. To Kip, it was a partial balancing of the books. ESAP's school day lasted forty minutes longer than Amdexter's. So let 'em think we're just going to run around and have fun. With his nose in the air, he broke his gaze from Founders.
...... At the head of a line of boys, Dr. Ralph led the way to the carousel and up to the weatherized control box. It had a keypad lock.
...... "This is going to be fun," said Kip to Wolfgang.
...... Wolfgang didn't answer, but stared with cat-like intensity at Dr. Ralph as he keyed the combination and swung open the cover. On a hook inside the cover, was a key to the control panel.
...... "A simple keypad lock protecting a key," said Wolfgang under his breath. "Dumb!"
...... Dr. Ralph inserted the key and panel lights came on. So too did the lights for the entire carousel. And the sound of carousel music filled the air. "Oops!" Dr. Ralph flipped two switches; the lights and music ceased. He passed out tennis balls with a caution. "No horse heroics, please. It would be embarrassing to fall off a carousel horse."
...... "Can we stand on the carousel?" said Kip. "I think it would be hard catching a ball sitting on a horse."
...... Dr. Ralph pursed his lips for a moment. "Okay. We'll try it. But be careful."
...... Most of the boys opted for standing and took places on the perimeter. Dr. Ralph started the carousel and the boys began throwing balls back and forth. Most of the balls were not caught and wound up littering the grass.
...... "No. No. This is chaos." Dr. Ralph stopped the carousel "There are too many boys riding. We need about a third of you to stay on the grass to field the balls and toss them back to the riders. Volunteers?"
...... No one volunteered.
...... "I guess I'll have to choose volunteers."
...... "I'll go," said Paul. "If I can borrow a pencil and a piece of paper."
...... "Here!" said a kid taking a notepad and ballpoint from his shirt pocket. "You can use these."
...... "Okay, then." Dr. Ralph pointed to other volunteers.
...... "Why?" whispered Kip who was standing next to Paul on the perimeter. "It'll be more fun here."
...... "Scouting--to see what talent we have for our baseball team." Paul hopped off the carousel and began collecting balls.
...... With about twenty boys on the carousel and ten on the grass, Dr. Ralph again switched the carousel into motion.
...... The system worked well. Riders threw to other riders. Balls flew off the carousel. Fielders retrieved grounded balls and tossed them back to the riders. As time went on, the percentage of balls caught grew. The riders were getting the hang of it at the expense of the fielders who had less and less to do.
...... "Hey, Dr. Ralph," called one of the riders. "Can we have music?"
...... "Well...." Dr. Ralph threw a glance across the Dalambertian. "Sure. Why not? We're far enough away from Founders that it shouldn't be a problem." He threw a switch and the sound of a carousel organ filled the air. The occasion was becoming festive.
...... At one point, Dr. Ralph exchanged fielders with riders. Paul though, said he'd rather remain in the field.
...... "This isn't exactly a game," said Dr. Ralph. "It's a physics experiment. So, up on the carousel with you."
...... After another quarter hour or so, the riders had become very accomplished at throwing and catching--and some began to show off with killer throws and jumping catches.
...... "Hey, catch this!" one boy challenged as he let off a vicious, but inaccurately thrown, fast ball.
...... The intended catcher made a great leap with both arms outstretched. He caught the ball, but couldn't regain his footing. He fell to the deck of the carousel and grabbed the pole supporting a horse. The horse began to come down, its hooves descending down over the boy. He shrieked, released the pole, and rolled out of the way. He rolled completely off the carousel and, with a yell and with arms and legs flailing, tumbled onto the grass.
...... "Oh, my god!" Dr. Ralph ran to the kid. "Nick. Are you hurt? Don't try to move."
...... Nick waved the man away and jumped to his feet. "It's okay. I'm fine."
...... Dr. Ralph, looking shaken, stopped the carousel and ordered the riders off. "Nick could have been seriously hurt."
...... "No, I couldn't," Nick protested. "I know judo. I know how to fall."
...... The kids laughed and Dr. Ralph threw a quick glance to the sky. "Music was a bad idea." He switched it off.
...... "You're not going to stop us from...experimenting on the carousel, Dr. Ralph," said Kip. "Are you?"
...... Dr. Ralph ran a hand through his hair. "No," he said. "It's part of the curriculum. But I've got to come up with a way to make it safe. I can't have another accident."
...... Paul, standing next to Kip, whispered, "I think I'm going to put Nick at shortstop."
...... As Dr. Ralph lectured his class on the absolute requirement of safety and caution, Kip looked idly across the Dalambertian to Founders Hall. He observed some faces in the windows looking back. Kip thought that Alex's might possibly be one of them.